The employee spent four weeks in the burns unit at Wakefield's Pinderfields Hospital following the incident at Yorkshire Fried Chicken, on Beeston Road in Beeston.
He needed extensive skin grafts to the left side of his body and has been told he could require further surgery.
Now, after a prosecution by Leeds City Council's environmental health team, the takeaway's owner has admitted breaching health and safety regulations.
Shazad Bashir was sentenced to 26 weeks in prison, suspended for 12 months, following a hearing at Leeds Magistrates' Court.
Magistrates heard that Bashir told staff not to call an ambulance after being informed about the accident over the phone.
Then, when he arrived on the scene, he took the man to hospital in a taxi - and asked him to say that he had suffered his injuries at home.
Bashir, whose company will have to pay £5,000 costs and a £150 victim surcharge on top of the £10,000 fine, yesterday told the Yorkshire Evening Post he was "very remorseful".
The accident happened after the unnamed worker drained the hot oil from the fryer and carried it in a plastic container to the takeaway's cellar so it could be poured into a large storage drum.
Magistrates were told that, as he attempted to empty the container, he slipped and spilt the oil over himself.
The court heard that the cellar was unlit, with the man using the light on his mobile phone to find his way to the drum.
Subsequent inspections by the council identified a number of serious breaches of health and safety regulations.
John Mulcahy, the council's chief officer with responsibility for environmental health, said: “This was a terrible incident that has left a man with life-changing injuries and which should never have happened.
“Everyone working in Leeds has the right to go about their jobs in an environment which is safe and where their employers have taken every precaution to ensure they are not at risk.
“I hope this sentence passed down by the courts sends a strong message to businesses in Leeds that we will not tolerate employers who flout regulations put in place for the safety of their staff and we will prosecute those who put employees in danger.”
Speaking yesterday at the takeaway, Bashir said he was "panicking" and "not thinking straight" when he asked the man to lie about where the accident had happened.
Bashir claimed his request for staff not to call an ambulance was due to a "misunderstanding" over the phone.
He also said the working practices at the takeaway had been changed to try to ensure there was never any repeat of the incident, which took place in August 2017.